Image sensor packages with folded cover-glass sealing interface

Abstract

An image sensor package with a folded cover-glass sealing interface includes (a) an image sensor with a light-receiving surface, (b) a substrate having (i) a recessed surface to which the image sensor is bonded, (ii) a second surface facing in a direction parallel to optical axis of the image sensor, surrounding the recessed surface, and being further than the light-receiving surface from the recessed surface, and (iii) a third surface facing the optical axis, and adjoining and surrounding the second surface, and (c) a cover glass bonded to the substrate with a folded sealing-interface at the second surface and the third surface.

What is claimed is: 
     
       1. An image sensor package with folded cover-glass sealing interface, comprising:
 an image sensor including a light-receiving surface; 
 a substrate including:
 a recessed surface to which the image sensor is bonded, 
 a second surface facing in a direction parallel to optical axis of the image sensor, surrounding the recessed surface, and being further than the light-receiving surface from the recessed surface, and 
 a third surface facing the optical axis, and adjoining and surrounding the second surface; and 
 
 a cover glass bonded to the substrate with a folded sealing interface at the second surface and the third surface, the folded sealing interface being simply connected and extending at least one millimeter along any path following contour of the folded sealing interface in direction away from the optical axis. 
 
     
     
       2. The image sensor package of  claim 1 , further including an adhesive at the folded sealing interface, for bonding the cover glass to the substrate. 
     
     
       3. The image sensor package of  claim 2 , the adhesive being a glue. 
     
     
       4. The image sensor package of  claim 1 , the third surface facing away from optical axis of the image sensor, the cover glass including:
 a planar surface facing the second surface; and 
 a rim extending away from plane of the planar surface to form an inward-facing surface that faces in direction toward the optical axis. 
 
     
     
       5. The image sensor package of  claim 4 , the inward-facing surface having height, in direction parallel to the optical axis, of at least 0.75 millimeters. 
     
     
       6. The image sensor package of  claim 5 , the second surface having width, along directions away from the optical axis, of no more than 0.45 millimeters. 
     
     
       7. An image sensor package with folded cover-glass sealing interface, comprising:
 an image sensor including a light-receiving surface; 
 a substrate including:
 a recessed surface to which the image sensor is bonded, 
 a second surface facing in a direction parallel to optical axis of the image sensor, surrounding the recessed surface, and being further than the light-receiving surface from the recessed surface, and 
 a third surface facing the optical axis and adjoining and surrounding the second surface; and 
 
 a cover glass bonded to the substrate with a folded sealing interface at the second surface and the third surface, the cover glass being planar and having (a) a bottom surface bonded to the second surface and (b) sides bonded to the third surface; 
 wherein (a) width of the second surface, along directions facing away from the image sensor, is no more than 0.5 millimeters, (b) height of the third surface is at least 0.75 millimeters, or (c) the width of the second surface is no more than 0.5 millimeters and the height of the third surface is at least 0.75 millimeters. 
 
     
     
       8. The image sensor package of  claim 7 , the height of the third surface being at least 0.75 millimeters and the cover glass having thickness of at least 0.75 millimeters. 
     
     
       9. The image sensor package of  claim 7 , the substrate including:
 a carrier sub-substrate forming at least a planar top surface and the recessed surface, the recessed surface being recessed from the planar top surface, the planar top surface including the second surface; and 
 a dam sub-substrate bonded to portion of the planar top surface adjoining the second surface, the dam sub-substrate having an aperture to form the third surface around the aperture. 
 
     
     
       10. A method for sealing a cover glass to a substrate of an image sensor package, comprising:
 bonding together a first sub-substrate and a second sub-substrate to form the substrate, the first sub-substrate forming at least a planar top surface and a recessed surface recessed from the planar top surface, the planar top surface including a second surface surrounding the recessed surface, the second surface facing in a first direction, the second sub-substrate having an aperture to form a third surface around the aperture, the third surface facing in second directions substantially orthogonal to the first direction, said bonding including bonding the first sub-substrate to portion of the planar top surface adjoining the second surface; 
 bonding an image sensor to the recessed surface such that (a) optical axis of the image sensor is parallel to the first direction and (b) light-receiving surface of the image sensor is closer than the second surface to the recessed surface; and 
 sealing the cover glass to the second surface and the third surface, such that the second surface and the third surface accommodate a folded sealing interface between the cover glass and the substrate. 
 
     
     
       11. The method of  claim 10 , the step of sealing comprising gluing the cover glass to the third surface and the second surface. 
     
     
       12. The method of  claim 10 , in the step of sealing, the folded sealing interface being simply connected. 
     
     
       13. The method of  claim 10 , the step of sealing comprising:
 sealing the second surface to a bottom surface of the cover glass; and 
 sealing the third surface to sides of the cover glass.